/*
 * Copyright (C), 2013, 上海汽车集团股份有限公司
 * FileName: ConnectionWrapper.java
 * Author:   12010065
 * Date:     2013年10月9日 下午2:03:55
 * Description: //模块目的、功能描述
 * History: //修改记录
 * <author>      <time>      <version>    <desc>
 * 修改人姓名             修改时间            版本号                  描述
 */
package com.ibm.framework.rws.wrapper;

import java.sql.Array;
import java.sql.Blob;
import java.sql.CallableStatement;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.NClob;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLClientInfoException;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.SQLXML;
import java.sql.Savepoint;
import java.sql.Statement;
import java.sql.Struct;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.Executor;

/**
 * 数据库连接池包装器
 * 
 * @author v_
 * 
 */
public class ConnectionWrapper implements Connection {

    /**
     * 当前连接
     */
    private Connection currentConnection;

    /**
     * 构造方法
     * 
     * @param currentConnection 当前连接
     */
    public ConnectionWrapper(Connection currentConnection) {
        super();
        this.currentConnection = currentConnection;
    }

    /**
     * Returns an object that implements the given interface to allow access to non-standard methods, or standard
     * methods not exposed by the proxy.
     * 
     * If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the
     * receiver is a wrapper and the wrapped object implements the interface then the result is the wrapped object or a
     * proxy for the wrapped object. Otherwise return the the result of calling <code>unwrap</code> recursively on the
     * wrapped object or a proxy for that result. If the receiver is not a wrapper and does not implement the interface,
     * then an <code>SQLException</code> is thrown.
     * 
     * @param iface A Class defining an interface that the result must implement.
     * @param <T> 泛型对象
     * @return an object that implements the interface. May be a proxy for the actual implementing object.
     * @throws SQLException If no object found that implements the interface
     * @since 1.6
     */
    public <T> T unwrap(Class<T> iface) throws SQLException {
        return currentConnection.unwrap(iface);
    }

    /**
     * Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an
     * object that does. Returns false otherwise. If this implements the interface then return true, else if this is a
     * wrapper then return the result of recursively calling <code>isWrapperFor</code> on the wrapped object. If this
     * does not implement the interface and is not a wrapper, return false. This method should be implemented as a
     * low-cost operation compared to <code>unwrap</code> so that callers can use this method to avoid expensive
     * <code>unwrap</code> calls that may fail. If this method returns true then calling <code>unwrap</code> with the
     * same argument should succeed.
     * 
     * @param iface a Class defining an interface.
     * @return true if this implements the interface or directly or indirectly wraps an object that does.
     * @throws SQLException if an error occurs while determining whether this is a wrapper for an object with the given
     *             interface.
     * @since 1.6
     */
    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        return currentConnection.isWrapperFor(iface);
    }

    /**
     * Creates a <code>Statement</code> object for sending SQL statements to the database. SQL statements without
     * parameters are normally executed using <code>Statement</code> objects. If the same SQL statement is executed many
     * times, it may be more efficient to use a <code>PreparedStatement</code> object.
     * <P>
     * Result sets created using the returned <code>Statement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @return a new default <code>Statement</code> object
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public Statement createStatement() throws SQLException {
        return currentConnection.createStatement();
    }

    /**
     * Creates a <code>PreparedStatement</code> object for sending parameterized SQL statements to the database.
     * <P>
     * A SQL statement with or without IN parameters can be pre-compiled and stored in a <code>PreparedStatement</code>
     * object. This object can then be used to efficiently execute this statement multiple times.
     * 
     * <P>
     * <B>Note:</B> This method is optimized for handling parametric SQL statements that benefit from precompilation. If
     * the driver supports precompilation, the method <code>prepareStatement</code> will send the statement to the
     * database for precompilation. Some drivers may not support precompilation. In this case, the statement may not be
     * sent to the database until the <code>PreparedStatement</code> object is executed. This has no direct effect on
     * users; however, it does affect which methods throw certain <code>SQLException</code> objects.
     * <P>
     * Result sets created using the returned <code>PreparedStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' IN parameter placeholders
     * @return a new default <code>PreparedStatement</code> object containing the pre-compiled SQL statement
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public PreparedStatement prepareStatement(String sql) throws SQLException {
        return new PreparedStatementWrapper(currentConnection.prepareStatement(sql));
    }

    /**
     * Creates a <code>CallableStatement</code> object for calling database stored procedures. The
     * <code>CallableStatement</code> object provides methods for setting up its IN and OUT parameters, and methods for
     * executing the call to a stored procedure.
     * 
     * <P>
     * <B>Note:</B> This method is optimized for handling stored procedure call statements. Some drivers may send the
     * call statement to the database when the method <code>prepareCall</code> is done; others may wait until the
     * <code>CallableStatement</code> object is executed. This has no direct effect on users; however, it does affect
     * which method throws certain SQLExceptions.
     * <P>
     * Result sets created using the returned <code>CallableStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' parameter placeholders. Typically this statement is
     *            specified using JDBC call escape syntax.
     * @return a new default <code>CallableStatement</code> object containing the pre-compiled SQL statement
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public CallableStatement prepareCall(String sql) throws SQLException {
        return currentConnection.prepareCall(sql);
    }

    /**
     * Converts the given SQL statement into the system's native SQL grammar. A driver may convert the JDBC SQL grammar
     * into its system's native SQL grammar prior to sending it. This method returns the native form of the statement
     * that the driver would have sent.
     * 
     * @param sql an SQL statement that may contain one or more '?' parameter placeholders
     * @return the native form of this statement
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public String nativeSQL(String sql) throws SQLException {
        return currentConnection.nativeSQL(sql);
    }

    /**
     * Sets this connection's auto-commit mode to the given state. If a connection is in auto-commit mode, then all its
     * SQL statements will be executed and committed as individual transactions. Otherwise, its SQL statements are
     * grouped into transactions that are terminated by a call to either the method <code>commit</code> or the method
     * <code>rollback</code> . By default, new connections are in auto-commit mode.
     * <P>
     * The commit occurs when the statement completes. The time when the statement completes depends on the type of SQL
     * Statement:
     * <ul>
     * <li>For DML statements, such as Insert, Update or Delete, and DDL statements, the statement is complete as soon
     * as it has finished executing.
     * <li>For Select statements, the statement is complete when the associated result set is closed.
     * <li>For <code>CallableStatement</code> objects or for statements that return multiple results, the statement is
     * complete when all of the associated result sets have been closed, and all update counts and output parameters
     * have been retrieved.
     * </ul>
     * <P>
     * <B>NOTE:</B> If this method is called during a transaction and the auto-commit mode is changed, the transaction
     * is committed. If <code>setAutoCommit</code> is called and the auto-commit mode is not changed, the call is a
     * no-op.
     * 
     * @param autoCommit <code>true</code> to enable auto-commit mode; <code>false</code> to disable it
     * @exception SQLException if a database access error occurs, setAutoCommit(true) is called while participating in a
     *                distributed transaction, or this method is called on a closed connection
     * @see #getAutoCommit
     */
    public void setAutoCommit(boolean autoCommit) throws SQLException {
        currentConnection.setAutoCommit(autoCommit);
    }

    /**
     * Retrieves the current auto-commit mode for this <code>Connection</code> object.
     * 
     * @return the current state of this <code>Connection</code> object's auto-commit mode
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @see #setAutoCommit
     */
    public boolean getAutoCommit() throws SQLException {
        return currentConnection.getAutoCommit();
    }

    /**
     * Makes all changes made since the previous commit/rollback permanent and releases any database locks currently
     * held by this <code>Connection</code> object. This method should be used only when auto-commit mode has been
     * disabled.
     * 
     * @exception SQLException if a database access error occurs, this method is called while participating in a
     *                distributed transaction, if this method is called on a closed conection or this
     *                <code>Connection</code> object is in auto-commit mode
     * @see #setAutoCommit
     */
    public void commit() throws SQLException {
        currentConnection.commit();
    }

    /**
     * Undoes all changes made in the current transaction and releases any database locks currently held by this
     * <code>Connection</code> object. This method should be used only when auto-commit mode has been disabled.
     * 
     * @exception SQLException if a database access error occurs, this method is called while participating in a
     *                distributed transaction, this method is called on a closed connection or this
     *                <code>Connection</code> object is in auto-commit mode
     * @see #setAutoCommit
     */
    public void rollback() throws SQLException {
        currentConnection.rollback();
    }

    /**
     * Releases this <code>Connection</code> object's database and JDBC resources immediately instead of waiting for
     * them to be automatically released.
     * <P>
     * Calling the method <code>close</code> on a <code>Connection</code> object that is already closed is a no-op.
     * <P>
     * It is <b>strongly recommended</b> that an application explicitly commits or rolls back an active transaction
     * prior to calling the <code>close</code> method. If the <code>close</code> method is called and there is an active
     * transaction, the results are implementation-defined.
     * <P>
     * 
     * @exception SQLException SQLException if a database access error occurs
     */
    public void close() throws SQLException {
        currentConnection.close();
    }

    /**
     * Retrieves whether this <code>Connection</code> object has been closed. A connection is closed if the method
     * <code>close</code> has been called on it or if certain fatal errors have occurred. This method is guaranteed to
     * return <code>true</code> only when it is called after the method <code>Connection.close</code> has been called.
     * <P>
     * This method generally cannot be called to determine whether a connection to a database is valid or invalid. A
     * typical client can determine that a connection is invalid by catching any exceptions that might be thrown when an
     * operation is attempted.
     * 
     * @return <code>true</code> if this <code>Connection</code> object is closed; <code>false</code> if it is still
     *         open
     * @exception SQLException if a database access error occurs
     */
    public boolean isClosed() throws SQLException {
        return currentConnection.isClosed();
    }

    /**
     * Retrieves a <code>DatabaseMetaData</code> object that contains metadata about the database to which this
     * <code>Connection</code> object represents a connection. The metadata includes information about the database's
     * tables, its supported SQL grammar, its stored procedures, the capabilities of this connection, and so on.
     * 
     * @return a <code>DatabaseMetaData</code> object for this <code>Connection</code> object
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public DatabaseMetaData getMetaData() throws SQLException {
        return currentConnection.getMetaData();
    }

    /**
     * Puts this connection in read-only mode as a hint to the driver to enable database optimizations.
     * 
     * <P>
     * <B>Note:</B> This method cannot be called during a transaction.
     * 
     * @param readOnly <code>true</code> enables read-only mode; <code>false</code> disables it
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or this
     *                method is called during a transaction
     */
    public void setReadOnly(boolean readOnly) throws SQLException {
        currentConnection.setReadOnly(readOnly);
    }

    /**
     * Retrieves whether this <code>Connection</code> object is in read-only mode.
     * 
     * @return <code>true</code> if this <code>Connection</code> object is read-only; <code>false</code> otherwise
     * @exception SQLException SQLException if a database access error occurs or this method is called on a closed
     *                connection
     */
    public boolean isReadOnly() throws SQLException {
        return currentConnection.isReadOnly();
    }

    /**
     * Retrieves whether this <code>Connection</code> object is in read-only mode.
     * 
     * @param catalog catalogs
     * @exception SQLException SQLException if a database access error occurs or this method is called on a closed
     *                connection
     */
    public void setCatalog(String catalog) throws SQLException {
        currentConnection.setCatalog(catalog);
    }

    /**
     * Retrieves this <code>Connection</code> object's current catalog name.
     * 
     * @return the current catalog name or <code>null</code> if there is none
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @see #setCatalog
     */
    public String getCatalog() throws SQLException {
        return currentConnection.getCatalog();
    }

    /**
     * Attempts to change the transaction isolation level for this <code>Connection</code> object to the one given. The
     * constants defined in the interface <code>Connection</code> are the possible transaction isolation levels.
     * <P>
     * <B>Note:</B> If this method is called during a transaction, the result is implementation-defined.
     * 
     * @param level one of the following <code>Connection</code> constants:
     *            <code>Connection.TRANSACTION_READ_UNCOMMITTED</code>,
     *            <code>Connection.TRANSACTION_READ_COMMITTED</code>,
     *            <code>Connection.TRANSACTION_REPEATABLE_READ</code>, or
     *            <code>Connection.TRANSACTION_SERIALIZABLE</code>. (Note that <code>Connection.TRANSACTION_NONE</code>
     *            cannot be used because it specifies that transactions are not supported.)
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameter is not one of the <code>Connection</code> constants
     * @see DatabaseMetaData#supportsTransactionIsolationLevel
     * @see #getTransactionIsolation
     */
    public void setTransactionIsolation(int level) throws SQLException {
        currentConnection.setTransactionIsolation(level);
    }

    /**
     * Retrieves this <code>Connection</code> object's current transaction isolation level.
     * 
     * @return the current transaction isolation level, which will be one of the following constants:
     *         <code>Connection.TRANSACTION_READ_UNCOMMITTED</code>, <code>Connection.TRANSACTION_READ_COMMITTED</code>,
     *         <code>Connection.TRANSACTION_REPEATABLE_READ</code>, <code>Connection.TRANSACTION_SERIALIZABLE</code>, or
     *         <code>Connection.TRANSACTION_NONE</code>.
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @see #setTransactionIsolation
     */
    public int getTransactionIsolation() throws SQLException {
        return currentConnection.getTransactionIsolation();
    }

    /**
     * Retrieves the first warning reported by calls on this <code>Connection</code> object. If there is more than one
     * warning, subsequent warnings will be chained to the first one and can be retrieved by calling the method
     * <code>SQLWarning.getNextWarning</code> on the warning that was retrieved previously.
     * <P>
     * This method may not be called on a closed connection; doing so will cause an <code>SQLException</code> to be
     * thrown.
     * 
     * <P>
     * <B>Note:</B> Subsequent warnings will be chained to this SQLWarning.
     * 
     * @return the first <code>SQLWarning</code> object or <code>null</code> if there are none
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @see SQLWarning
     */
    public SQLWarning getWarnings() throws SQLException {
        return currentConnection.getWarnings();
    }

    /**
     * Clears all warnings reported for this <code>Connection</code> object. After a call to this method, the method
     * <code>getWarnings</code> returns <code>null</code> until a new warning is reported for this
     * <code>Connection</code> object.
     * 
     * @exception SQLException SQLException if a database access error occurs or this method is called on a closed
     *                connection
     */
    public void clearWarnings() throws SQLException {
        currentConnection.clearWarnings();
    }

    /**
     * Creates a <code>Statement</code> object that will generate <code>ResultSet</code> objects with the given type and
     * concurrency. This method is the same as the <code>createStatement</code> method above, but it allows the default
     * result set type and concurrency to be overridden. The holdability of the created result sets can be determined by
     * calling {@link #getHoldability}.
     * 
     * @param resultSetType a result set type; one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *            <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency a concurrency type; one of <code>ResultSet.CONCUR_READ_ONLY</code> or
     *            <code>ResultSet.CONCUR_UPDATABLE</code>
     * @return a new <code>Statement</code> object that will generate <code>ResultSet</code> objects with the given type
     *         and concurrency
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameters are not <code>ResultSet</code> constants indicating type and concurrency
     * @since 1.2
     */
    public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
        return currentConnection.createStatement(resultSetType, resultSetConcurrency);
    }

    /**
     * 
     * Creates a <code>PreparedStatement</code> object that will generate <code>ResultSet</code> objects with the given
     * type and concurrency. This method is the same as the <code>prepareStatement</code> method above, but it allows
     * the default result set type and concurrency to be overridden. The holdability of the created result sets can be
     * determined by calling {@link #getHoldability}.
     * 
     * @param sql a <code>String</code> object that is the SQL statement to be sent to the database; may contain one or
     *            more '?' IN parameters
     * @param resultSetType a result set type; one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *            <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency a concurrency type; one of <code>ResultSet.CONCUR_READ_ONLY</code> or
     *            <code>ResultSet.CONCUR_UPDATABLE</code>
     * @return a new PreparedStatement object containing the pre-compiled SQL statement that will produce
     *         <code>ResultSet</code> objects with the given type and concurrency
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameters are not <code>ResultSet</code> constants indicating type and concurrency
     * @since 1.2
     */
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency)
            throws SQLException {
        return new PreparedStatementWrapper(
                currentConnection.prepareStatement(sql, resultSetType, resultSetConcurrency));
    }

    /**
     * Creates a <code>CallableStatement</code> object for calling database stored procedures. The
     * <code>CallableStatement</code> object provides methods for setting up its IN and OUT parameters, and methods for
     * executing the call to a stored procedure.
     * 
     * <P>
     * <B>Note:</B> This method is optimized for handling stored procedure call statements. Some drivers may send the
     * call statement to the database when the method <code>prepareCall</code> is done; others may wait until the
     * <code>CallableStatement</code> object is executed. This has no direct effect on users; however, it does affect
     * which method throws certain SQLExceptions.
     * <P>
     * Result sets created using the returned <code>CallableStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' parameter placeholders. Typically this statement is
     *            specified using JDBC call escape syntax.
     * @param resultSetType resultSetTypes
     * @param resultSetConcurrency resultSetConcurrencys
     * @return a new default <code>CallableStatement</code> object containing the pre-compiled SQL statement
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     */
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
        return currentConnection.prepareCall(sql);
    }

    /**
     * Retrieves the <code>Map</code> object associated with this <code>Connection</code> object. Unless the application
     * has added an entry, the type map returned will be empty.
     * <p>
     * You must invoke <code>setTypeMap</code> after making changes to the <code>Map</code> object returned from
     * <code>getTypeMap</code> as a JDBC driver may create an internal copy of the <code>Map</code> object passed to
     * <code>setTypeMap</code>:
     * <p>
     * 
     * <pre>
     * Map&lt;String, Class&lt;?&gt;&gt; myMap = con.getTypeMap();
     * myMap.put(&quot;mySchemaName.ATHLETES&quot;, Athletes.class);
     * con.setTypeMap(myMap);
     * </pre>
     * 
     * @return the <code>java.util.Map</code> object associated with this <code>Connection</code> object
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @since 1.2
     * @see #setTypeMap
     */
    public Map<String, Class<?>> getTypeMap() throws SQLException {
        return currentConnection.getTypeMap();
    }

    /**
     * Installs the given <code>TypeMap</code> object as the type map for this <code>Connection</code> object. The type
     * map will be used for the custom mapping of SQL structured types and distinct types.
     * <p>
     * You must set the the values for the <code>TypeMap</code> prior to callng <code>setMap</code> as a JDBC driver may
     * create an internal copy of the <code>TypeMap</code>:
     * <p>
     * 
     * <pre>
     *      Map myMap&lt;String,Class&lt;?&gt;&gt; = new HashMap&lt;String,Class&lt;?&gt;&gt;();
     *      myMap.put("mySchemaName.ATHLETES", Athletes.class);
     *      con.setTypeMap(myMap);
     * </pre>
     * 
     * @param map the <code>java.util.Map</code> object to install as the replacement for this <code>Connection</code>
     *            object's default type map
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameter is not a <code>java.util.Map</code> object
     * @since 1.2
     * @see #getTypeMap
     */
    public void setTypeMap(Map<String, Class<?>> map) throws SQLException {
        currentConnection.setTypeMap(map);
    }

    /**
     * Changes the default holdability of <code>ResultSet</code> objects created using this <code>Connection</code>
     * object to the given holdability. The default holdability of <code>ResultSet</code> objects can be be determined
     * by invoking {@link DatabaseMetaData#getResultSetHoldability}.
     * 
     * @param holdability a <code>ResultSet</code> holdability constant; one of
     *            <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @throws SQLException if a database access occurs, this method is called on a closed connection, or the given
     *             parameter is not a <code>ResultSet</code> constant indicating holdability
     * @see #getHoldability
     * @see DatabaseMetaData#getResultSetHoldability
     * @see ResultSet
     * @since 1.4
     */
    public void setHoldability(int holdability) throws SQLException {
        currentConnection.setHoldability(holdability);
    }

    /**
     * Retrieves the current holdability of <code>ResultSet</code> objects created using this <code>Connection</code>
     * object.
     * 
     * @return the holdability, one of <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
     *         <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @throws SQLException if a database access error occurs or this method is called on a closed connection
     * @see #setHoldability
     * @see DatabaseMetaData#getResultSetHoldability
     * @see ResultSet
     * @since 1.4
     */
    public int getHoldability() throws SQLException {
        return currentConnection.getHoldability();
    }

    /**
     * Creates an unnamed savepoint in the current transaction and returns the new <code>Savepoint</code> object that
     * represents it.
     * 
     * <p>
     * if setSavepoint is invoked outside of an active transaction, a transaction will be started at this newly created
     * savepoint.
     * 
     * @return the new <code>Savepoint</code> object
     * @exception SQLException if a database access error occurs, this method is called while participating in a
     *                distributed transaction, this method is called on a closed connection or this
     *                <code>Connection</code> object is currently in auto-commit mode
     * @see Savepoint
     * @since 1.4
     */
    public Savepoint setSavepoint() throws SQLException {
        return currentConnection.setSavepoint();
    }

    /**
     * Creates a savepoint with the given name in the current transaction and returns the new <code>Savepoint</code>
     * object that represents it.
     * 
     * <p>
     * if setSavepoint is invoked outside of an active transaction, a transaction will be started at this newly created
     * savepoint.
     * 
     * @param name a <code>String</code> containing the name of the savepoint
     * @return the new <code>Savepoint</code> object
     * @exception SQLException if a database access error occurs, this method is called while participating in a
     *                distributed transaction, this method is called on a closed connection or this
     *                <code>Connection</code> object is currently in auto-commit mode
     * @see Savepoint
     * @since 1.4
     */
    public Savepoint setSavepoint(String name) throws SQLException {
        return currentConnection.setSavepoint(name);
    }

    /**
     * Undoes all changes made after the given <code>Savepoint</code> object was set.
     * <P>
     * This method should be used only when auto-commit has been disabled.
     * 
     * @param savepoint the <code>Savepoint</code> object to roll back to
     * @exception SQLException if a database access error occurs, this method is called while participating in a
     *                distributed transaction, this method is called on a closed connection, the <code>Savepoint</code>
     *                object is no longer valid, or this <code>Connection</code> object is currently in auto-commit mode
     * @see Savepoint
     * @see #rollback
     * @since 1.4
     */
    public void rollback(Savepoint savepoint) throws SQLException {
        currentConnection.rollback(savepoint);
    }

    /**
     * Removes the specified <code>Savepoint</code> and subsequent <code>Savepoint</code> objects from the current
     * transaction. Any reference to the savepoint after it have been removed will cause an <code>SQLException</code> to
     * be thrown.
     * 
     * @param savepoint the <code>Savepoint</code> object to be removed
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given <code>Savepoint</code> object is not a valid savepoint in the current transaction
     * @since 1.4
     */
    public void releaseSavepoint(Savepoint savepoint) throws SQLException {
        currentConnection.releaseSavepoint(savepoint);
    }

    /**
     * Creates a <code>Statement</code> object that will generate <code>ResultSet</code> objects with the given type,
     * concurrency, and holdability. This method is the same as the <code>createStatement</code> method above, but it
     * allows the default result set type, concurrency, and holdability to be overridden.
     * 
     * @param resultSetType one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.TYPE_FORWARD_ONLY</code>, <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *            <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.CONCUR_READ_ONLY</code> or <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param resultSetHoldability one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @return a new <code>Statement</code> object that will generate <code>ResultSet</code> objects with the given
     *         type, concurrency, and holdability
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameters are not <code>ResultSet</code> constants indicating type, concurrency, and
     *                holdability
     * @see ResultSet
     * @since 1.4
     */
    public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability)
            throws SQLException {
        return currentConnection.createStatement(resultSetType, resultSetConcurrency, resultSetHoldability);
    }

    /**
     * 
     * Creates a <code>PreparedStatement</code> object that will generate <code>ResultSet</code> objects with the given
     * type and concurrency. This method is the same as the <code>prepareStatement</code> method above, but it allows
     * the default result set type and concurrency to be overridden. The holdability of the created result sets can be
     * determined by calling {@link #getHoldability}.
     * 
     * @param sql a <code>String</code> object that is the SQL statement to be sent to the database; may contain one or
     *            more '?' IN parameters
     * @param resultSetType a result set type; one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *            <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency a concurrency type; one of <code>ResultSet.CONCUR_READ_ONLY</code> or
     *            <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param resultSetHoldability resultSetHoldabilitys
     * @return a new PreparedStatement object containing the pre-compiled SQL statement that will produce
     *         <code>ResultSet</code> objects with the given type and concurrency
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameters are not <code>ResultSet</code> constants indicating type and concurrency
     * @since 1.2
     */
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency,
            int resultSetHoldability) throws SQLException {
        return new PreparedStatementWrapper(
                currentConnection.prepareStatement(sql, resultSetType, resultSetConcurrency));
    }

    /**
     * Creates a <code>CallableStatement</code> object that will generate <code>ResultSet</code> objects with the given
     * type and concurrency. This method is the same as the <code>prepareCall</code> method above, but it allows the
     * default result set type, result set concurrency type and holdability to be overridden.
     * 
     * @param sql a <code>String</code> object that is the SQL statement to be sent to the database; may contain on or
     *            more '?' parameters
     * @param resultSetType one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.TYPE_FORWARD_ONLY</code>, <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *            <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.CONCUR_READ_ONLY</code> or <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param resultSetHoldability one of the following <code>ResultSet</code> constants:
     *            <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @return a new <code>CallableStatement</code> object, containing the pre-compiled SQL statement, that will
     *         generate <code>ResultSet</code> objects with the given type, concurrency, and holdability
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameters are not <code>ResultSet</code> constants indicating type, concurrency, and
     *                holdability
     * @see ResultSet
     * @since 1.4
     */
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency,
            int resultSetHoldability) throws SQLException {
        return currentConnection.prepareCall(sql, resultSetType, resultSetConcurrency, resultSetHoldability);
    }

    /**
     * Creates a default <code>PreparedStatement</code> object that has the capability to retrieve auto-generated keys.
     * The given constant tells the driver whether it should make auto-generated keys available for retrieval. This
     * parameter is ignored if the SQL statement is not an <code>INSERT</code> statement, or an SQL statement able to
     * return auto-generated keys (the list of such statements is vendor-specific).
     * <P>
     * <B>Note:</B> This method is optimized for handling parametric SQL statements that benefit from precompilation. If
     * the driver supports precompilation, the method <code>prepareStatement</code> will send the statement to the
     * database for precompilation. Some drivers may not support precompilation. In this case, the statement may not be
     * sent to the database until the <code>PreparedStatement</code> object is executed. This has no direct effect on
     * users; however, it does affect which methods throw certain SQLExceptions.
     * <P>
     * Result sets created using the returned <code>PreparedStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' IN parameter placeholders
     * @param autoGeneratedKeys a flag indicating whether auto-generated keys should be returned; one of
     *            <code>Statement.RETURN_GENERATED_KEYS</code> or <code>Statement.NO_GENERATED_KEYS</code>
     * @return a new <code>PreparedStatement</code> object, containing the pre-compiled SQL statement, that will have
     *         the capability of returning auto-generated keys
     * @exception SQLException if a database access error occurs, this method is called on a closed connection or the
     *                given parameter is not a <code>Statement</code> constant indicating whether auto-generated keys
     *                should be returned
     * @since 1.4
     */
    public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) throws SQLException {
        return new PreparedStatementWrapper(currentConnection.prepareStatement(sql, autoGeneratedKeys));
    }

    /**
     * Creates a default <code>PreparedStatement</code> object capable of returning the auto-generated keys designated
     * by the given array. This array contains the indexes of the columns in the target table that contain the
     * auto-generated keys that should be made available. The driver will ignore the array if the SQL statement is not
     * an <code>INSERT</code> statement, or an SQL statement able to return auto-generated keys (the list of such
     * statements is vendor-specific).
     * <p>
     * An SQL statement with or without IN parameters can be pre-compiled and stored in a <code>PreparedStatement</code>
     * object. This object can then be used to efficiently execute this statement multiple times.
     * <P>
     * <B>Note:</B> This method is optimized for handling parametric SQL statements that benefit from precompilation. If
     * the driver supports precompilation, the method <code>prepareStatement</code> will send the statement to the
     * database for precompilation. Some drivers may not support precompilation. In this case, the statement may not be
     * sent to the database until the <code>PreparedStatement</code> object is executed. This has no direct effect on
     * users; however, it does affect which methods throw certain SQLExceptions.
     * <P>
     * Result sets created using the returned <code>PreparedStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' IN parameter placeholders
     * @param columnIndexes an array of column indexes indicating the columns that should be returned from the inserted
     *            row or rows
     * @return a new <code>PreparedStatement</code> object, containing the pre-compiled statement, that is capable of
     *         returning the auto-generated keys designated by the given array of column indexes
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @since 1.4
     */
    public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException {
        return new PreparedStatementWrapper(currentConnection.prepareStatement(sql, columnIndexes));
    }

    /**
     * Creates a default <code>PreparedStatement</code> object capable of returning the auto-generated keys designated
     * by the given array. This array contains the names of the columns in the target table that contain the
     * auto-generated keys that should be returned. The driver will ignore the array if the SQL statement is not an
     * <code>INSERT</code> statement, or an SQL statement able to return auto-generated keys (the list of such
     * statements is vendor-specific).
     * <P>
     * An SQL statement with or without IN parameters can be pre-compiled and stored in a <code>PreparedStatement</code>
     * object. This object can then be used to efficiently execute this statement multiple times.
     * <P>
     * <B>Note:</B> This method is optimized for handling parametric SQL statements that benefit from precompilation. If
     * the driver supports precompilation, the method <code>prepareStatement</code> will send the statement to the
     * database for precompilation. Some drivers may not support precompilation. In this case, the statement may not be
     * sent to the database until the <code>PreparedStatement</code> object is executed. This has no direct effect on
     * users; however, it does affect which methods throw certain SQLExceptions.
     * <P>
     * Result sets created using the returned <code>PreparedStatement</code> object will by default be type
     * <code>TYPE_FORWARD_ONLY</code> and have a concurrency level of <code>CONCUR_READ_ONLY</code>. The holdability of
     * the created result sets can be determined by calling {@link #getHoldability}.
     * 
     * @param sql an SQL statement that may contain one or more '?' IN parameter placeholders
     * @param columnNames an array of column names indicating the columns that should be returned from the inserted row
     *            or rows
     * @return a new <code>PreparedStatement</code> object, containing the pre-compiled statement, that is capable of
     *         returning the auto-generated keys designated by the given array of column names
     * @exception SQLException if a database access error occurs or this method is called on a closed connection
     * @since 1.4
     */
    public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException {
        return new PreparedStatementWrapper(currentConnection.prepareStatement(sql, columnNames));
    }

    /**
     * Constructs an object that implements the <code>Clob</code> interface. The object returned initially contains no
     * data. The <code>setAsciiStream</code>, <code>setCharacterStream</code> and <code>setString</code> methods of the
     * <code>Clob</code> interface may be used to add data to the <code>Clob</code>.
     * 
     * @return An object that implements the <code>Clob</code> interface
     * @throws SQLException if an object that implements the <code>Clob</code> interface can not be constructed, this
     *             method is called on a closed connection or a database access error occurs.
     * @since 1.6
     */
    public Clob createClob() throws SQLException {
        return currentConnection.createClob();
    }

    /**
     * Constructs an object that implements the <code>Blob</code> interface. The object returned initially contains no
     * data. The <code>setBinaryStream</code> and <code>setBytes</code> methods of the <code>Blob</code> interface may
     * be used to add data to the <code>Blob</code>.
     * 
     * @return An object that implements the <code>Blob</code> interface
     * @throws SQLException if an object that implements the <code>Blob</code> interface can not be constructed, this
     *             method is called on a closed connection or a database access error occurs.
     * @since 1.6
     */
    public Blob createBlob() throws SQLException {
        return currentConnection.createBlob();
    }

    /**
     * Constructs an object that implements the <code>NClob</code> interface. The object returned initially contains no
     * data. The <code>setAsciiStream</code>, <code>setCharacterStream</code> and <code>setString</code> methods of the
     * <code>NClob</code> interface may be used to add data to the <code>NClob</code>.
     * 
     * @return An object that implements the <code>NClob</code> interface
     * @throws SQLException if an object that implements the <code>NClob</code> interface can not be constructed, this
     *             method is called on a closed connection or a database access error occurs.
     * @since 1.6
     */
    public NClob createNClob() throws SQLException {
        return currentConnection.createNClob();
    }

    /**
     * Constructs an object that implements the <code>SQLXML</code> interface. The object returned initially contains no
     * data. The <code>createXmlStreamWriter</code> object and <code>setString</code> method of the <code>SQLXML</code>
     * interface may be used to add data to the <code>SQLXML</code> object.
     * 
     * @return An object that implements the <code>SQLXML</code> interface
     * @throws SQLException if an object that implements the <code>SQLXML</code> interface can not be constructed, this
     *             method is called on a closed connection or a database access error occurs.
     * @since 1.6
     */
    public SQLXML createSQLXML() throws SQLException {
        return currentConnection.createSQLXML();
    }

    /**
     * Returns true if the connection has not been closed and is still valid. The driver shall submit a query on the
     * connection or use some other mechanism that positively verifies the connection is still valid when this method is
     * called.
     * <p>
     * The query submitted by the driver to validate the connection shall be executed in the context of the current
     * transaction.
     * 
     * @param timeout - The time in seconds to wait for the database operation used to validate the connection to
     *            complete. If the timeout period expires before the operation completes, this method returns false. A
     *            value of 0 indicates a timeout is not applied to the database operation.
     *            <p>
     * @return true if the connection is valid, false otherwise
     * @exception SQLException if the value supplied for <code>timeout</code> is less then 0
     * @since 1.6
     *        <p>
     * @see DatabaseMetaData#getClientInfoProperties
     */
    public boolean isValid(int timeout) throws SQLException {
        return currentConnection.isValid(timeout);
    }

    /**
     * Sets the value of the client info property specified by name to the value specified by value.
     * <p>
     * Applications may use the <code>DatabaseMetaData.getClientInfoProperties</code> method to determine the client
     * info properties supported by the driver and the maximum length that may be specified for each property.
     * <p>
     * The driver stores the value specified in a suitable location in the database. For example in a special register,
     * session parameter, or system table column. For efficiency the driver may defer setting the value in the database
     * until the next time a statement is executed or prepared. Other than storing the client information in the
     * appropriate place in the database, these methods shall not alter the behavior of the connection in anyway. The
     * values supplied to these methods are used for accounting, diagnostics and debugging purposes only.
     * <p>
     * The driver shall generate a warning if the client info name specified is not recognized by the driver.
     * <p>
     * If the value specified to this method is greater than the maximum length for the property the driver may either
     * truncate the value and generate a warning or generate a <code>SQLClientInfoException</code>. If the driver
     * generates a <code>SQLClientInfoException</code>, the value specified was not set on the connection.
     * <p>
     * The following are standard client info properties. Drivers are not required to support these properties however
     * if the driver supports a client info property that can be described by one of the standard properties, the
     * standard property name should be used.
     * <p>
     * <ul>
     * <li>ApplicationName - The name of the application currently utilizing the connection</li>
     * <li>ClientUser - The name of the user that the application using the connection is performing work for. This may
     * not be the same as the user name that was used in establishing the connection.</li>
     * <li>ClientHostname - The hostname of the computer the application using the connection is running on.</li>
     * </ul>
     * <p>
     * 
     * @param name The name of the client info property to set
     * @param value The value to set the client info property to. If the value is null, the current value of the
     *            specified property is cleared.
     *            <p>
     * @throws SQLClientInfoException if the database server returns an error while setting the client info value on the
     *             database server or this method is called on a closed connection
     *             <p>
     * @since 1.6
     */
    public void setClientInfo(String name, String value) throws SQLClientInfoException {
        currentConnection.setClientInfo(name, value);
    }

    /**
     * Sets the value of the connection's client info properties. The <code>Properties</code> object contains the names
     * and values of the client info properties to be set. The set of client info properties contained in the properties
     * list replaces the current set of client info properties on the connection. If a property that is currently set on
     * the connection is not present in the properties list, that property is cleared. Specifying an empty properties
     * list will clear all of the properties on the connection. See <code>setClientInfo (String, String)</code> for more
     * information.
     * <p>
     * If an error occurs in setting any of the client info properties, a <code>SQLClientInfoException</code> is thrown.
     * The <code>SQLClientInfoException</code> contains information indicating which client info properties were not
     * set. The state of the client information is unknown because some databases do not allow multiple client info
     * properties to be set atomically. For those databases, one or more properties may have been set before the error
     * occurred.
     * <p>
     * 
     * @param properties the list of client info properties to set
     *            <p>
     * @see Connection#setClientInfo(String, String) setClientInfo(String, String)
     * @since 1.6
     *        <p>
     * @throws SQLClientInfoException if the database server returns an error while setting the clientInfo values on the
     *             database server or this method is called on a closed connection
     *             <p>
     */
    public void setClientInfo(Properties properties) throws SQLClientInfoException {
        currentConnection.setClientInfo(properties);
    }

    /**
     * Returns the value of the client info property specified by name. This method may return null if the specified
     * client info property has not been set and does not have a default value. This method will also return null if the
     * specified client info property name is not supported by the driver.
     * <p>
     * Applications may use the <code>DatabaseMetaData.getClientInfoProperties</code> method to determine the client
     * info properties supported by the driver.
     * <p>
     * 
     * @param name The name of the client info property to retrieve
     *            <p>
     * @return The value of the client info property specified
     *         <p>
     * @throws SQLException if the database server returns an error when fetching the client info value from the
     *             database or this method is called on a closed connection
     *             <p>
     * @since 1.6
     *        <p>
     * @see DatabaseMetaData#getClientInfoProperties
     */
    public String getClientInfo(String name) throws SQLException {
        return currentConnection.getClientInfo(name);
    }

    /**
     * Returns a list containing the name and current value of each client info property supported by the driver. The
     * value of a client info property may be null if the property has not been set and does not have a default value.
     * <p>
     * 
     * @return A <code>Properties</code> object that contains the name and current value of each of the client info
     *         properties supported by the driver.
     *         <p>
     * @throws SQLException if the database server returns an error when fetching the client info values from the
     *             database or this method is called on a closed connection
     *             <p>
     * @since 1.6
     */
    public Properties getClientInfo() throws SQLException {
        return currentConnection.getClientInfo();
    }

    /**
     * Factory method for creating Array objects.
     * <p>
     * <b>Note: </b>When <code>createArrayOf</code> is used to create an array object that maps to a primitive data
     * type, then it is implementation-defined whether the <code>Array</code> object is an array of that primitive data
     * type or an array of <code>Object</code>.
     * <p>
     * <b>Note: </b>The JDBC driver is responsible for mapping the elements <code>Object</code> array to the default
     * JDBC SQL type defined in java.sql.Types for the given class of <code>Object</code>. The default mapping is
     * specified in Appendix B of the JDBC specification. If the resulting JDBC type is not the appropriate type for the
     * given typeName then it is implementation defined whether an <code>SQLException</code> is thrown or the driver
     * supports the resulting conversion.
     * 
     * @param typeName the SQL name of the type the elements of the array map to. The typeName is a database-specific
     *            name which may be the name of a built-in type, a user-defined type or a standard SQL type supported by
     *            this database. This is the value returned by <code>Array.getBaseTypeName</code>
     * @param elements the elements that populate the returned object
     * @return an Array object whose elements map to the specified SQL type
     * @throws SQLException if a database error occurs, the JDBC type is not appropriate for the typeName and the
     *             conversion is not supported, the typeName is null or this method is called on a closed connection
     * @since 1.6
     */
    public Array createArrayOf(String typeName, Object[] elements) throws SQLException {
        return currentConnection.createArrayOf(typeName, elements);
    }

    /**
     * Factory method for creating Struct objects.
     * 
     * @param typeName the SQL type name of the SQL structured type that this <code>Struct</code> object maps to. The
     *            typeName is the name of a user-defined type that has been defined for this database. It is the value
     *            returned by <code>Struct.getSQLTypeName</code>.
     * 
     * @param attributes the attributes that populate the returned object
     * @return a Struct object that maps to the given SQL type and is populated with the given attributes
     * @throws SQLException if a database error occurs, the typeName is null or this method is called on a closed
     *             connection
     * @since 1.6
     */
    public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
        return currentConnection.createStruct(typeName, attributes);
    }

    /**
     * 设置表空间
     * 
     * @param schema 表空间
     * @exception SQLException SQL异常
     */
    @Override
    public void setSchema(String schema) throws SQLException {
        // TODO Auto-generated method stub

    }

    /**
     * 获取表空间
     * 
     * @return 表空间
     * @exception SQLException SQL异常
     */
    @Override
    public String getSchema() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }

    /**
     * 放弃执行
     * 
     * @param executor 数据库任务执行者
     * @exception SQLException SQL异常
     */
    @Override
    public void abort(Executor executor) throws SQLException {
        // TODO Auto-generated method stub

    }

    /**
     * 设置连接超时时间
     * 
     * @param executor 任务执行者
     * @param milliseconds 连接超时时间
     * @exception SQLException SQL异常
     */
    @Override
    public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException {
        // TODO Auto-generated method stub

    }

    /**
     * 获取连接超时时间
     * 
     * @return 连接超时时间
     * @exception SQLException SQL异常
     */
    @Override
    public int getNetworkTimeout() throws SQLException {
        // TODO Auto-generated method stub
        return 0;
    }

}
